Nitric Oxide: Detection Methods and Possible Roles During Jasmonate-Regulated Stress Response

Nitric oxide (NO) has been involved in modulation of signaling pathways under biotic and abiotic stress responses. NO synthesis, detection methods and mechanism of action are briefly introduced. Studies on the comparison of jasmonates, 12-oxophytodienoic acid (OPDA), and ABA content and of gene expression variation in chickpea roots from a drought tolerant and a responsive variety have extended studies on drought and salt stress on other chickpea varieties, confirming the opinion of involvement of upregulation of specific LOX, AOS, and hydroperoxyde lyase (HPL) isoforms. In this context, various levels of regulation of NO on jasmonate (JA) signaling and JA biosynthesis pathway are reviewed and discussed. Finally, an additional level of regulation by epigenetics and microRNAs, with the involvement of abscisic acid and NO-responsive elements in promoters of transcription factor genes, is briefly introduced.